HIV hides soon after infection, UNC research shows

May 29, 2012

While current therapies are effective at controlling HIV, some virus remains hidden in certain CD4+ T cells, specialized immune system cells in which the virus replicates itself. This latent infection remains a significant challenge to curing HIV.A team of researchers from the University of North Carolina schools of medicine and public health has demonstrated that latency develops soon after infection and slows when antiretroviral therapy is given.

The team studied 27 patients with acute HIV infection (AHI). AHI occurs soon after exposure, when virus is found in blood plasma but antibodies are not yet detectible. All but one of the patients studied had been infected within the previous 45 days. The study team developed a mathematical model to predict how often latent cells were infected based upon when antiretroviral therapy (ART) was started. They found that early treatment reduced production of latently infected cells.

In addition, the researchers determined that there are two types of latently infected cells, one short-lived, but another extremely durable. The authors refer to the latter as “deep” latent infection.

Dr. David Margolis

“We found that latent infection decayed in some patients, but that all had a few deeply latent infected cells,” said senior author David Margolis, MD, professor of medicine, microbiology and immunology in the medical school and of epidemiology at UNC Gillings School of Global Public Health. “These are the cells that we must eliminate to cure infection.”

The team made other hopeful observations. “The immune response of some patients appears to play a role in limiting the size of the latent reservoir,” said Nancie Archin, PhD, the study’s lead author and a research scientist at the medical school. “Efforts to improve the immune response to prevent HIV infection may also teach us to eradicate it.”

The research was conducted through the Center for HIV/AIDS Vaccine Immunology and as part of a UNC-led consortium, the Collaboratory of AIDS Researchers for Eradication (CARE), funded by the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health (NIH). The consortium is administered by the North Carolina Translational and Clinical Sciences (NC TraCS) Institute at UNC, one of 60 medical research institutions in the U.S. working to improve biomedical research through the NIH Clinical and Translational Science Awards (CTSA) program.

Other UNC co-authors include Myron Cohen, MD, J. Herbert Bate Distinguished Professor of Medicine, Microbiology and Immunology in the medical school and of epidemiology in the public health school; and Joann Kuruc, MSN, Abigail Liberty, Cynthia L. Gay, MD, and Joseph Eron, MD, all from the medical school.

Funding for the research was provided by the Center for HIV/AIDS Vaccine Immunology, the National Institutes of Health, and the James B. Pendleton Charitable Trust.